That's quite interesting, it's true that the block size for BTC is fairly large.
Personally, I haven't used ETH for payment yet. For larger amounts I just use BTC and for smaller payments I use Bitcoin Cash BCH.
What are your thoughts on BTC vs ETH?
It will be quiet interesting if you'll use Bitcoin & Ethereum at the same time as a payment method. For faster transaction if it's peer-to-peer or third-party-programs; you might wanna recommend to use Ethereum for quick transaction. In the other hand, Bitcoin is kinda sluggish for blockchain transaction.